Is it okay for my cat to eat a few bites of dog food?

My cat still eats his regular food, but sometimes he eats a few bites out of the dogs bowl. I know that dog food doesnt have the tuarine that cat food does, but Im not worried about that since the cat still eats his own food. Ive read that the pH level of dog food can lead to urinary problems in cats. Is this true? Do I need to worry about his eating a few bites from the dog bowl?